Firing mechanism with a rearwardly activated firing pin

ABSTRACT

A firing mechanism in small arms of the type, which use miniature rifle cartridges which present an annular detonating fuse located in the rim of the cartridge case, includes a trigger and a movement transmitting device which cause the firing pin to strike the rim of the cartridge to set off the detonating fuse. The striking pin is directed from the front, and moves backwards to the rim of the cartridge case.

Unite States Patent Joel Lehtinen Karhula, Jumalniemi, Finland 765,433

Oct. 7, 1 968 Mar. 23, 1971 0y Sako AB Riihimaki, Finland Inventor Appl,No. Filed Patented Assignee FIRING MECHANISM WITH A REARWARDLY ACTIVATEDFIRING PIN 10 Claims, 1 Drawing Fig.

US. Cl 42/69, 42/ 1 Int. Cl F4lc 3/00, F4lc 11/02, F4lc 19/00 Field ofSearch 42/69, 69 (B), 1,] (G)-1 (K), 2; 89/1, 1.01; 227/9-l1 mar new.

[56] References Cited UNITED STATES PATENTS 2,099,993 1 H1937 Tauschek42/1 2,931,039 4/1960 Henning et al.. 227/1 I 3,087,428 4/1963 Frech,Jr. 42/69 3,286,899 1 H1966 Seghezzi et a1. 227/ 1 0 PrimaryExaminer-Samuel F einberg Assistant Examiner-Charles T. JordanAttorney-Waters, Roditi, Schwartz & Nissen ABSTRACT: A firing mechanismin small arms of the type, which use miniature rifle cartridges whichpresent an annular detonating fuse located in the rim of the cartridgecase, includes a trigger and a movement transmitting device which causethe firing pin to strike the rim of the cartridge to set off thedetonating fuse. The striking pin is directed from the front, and movesbackwards to the rim of the cartridge case.

Known firearms present a firing mechanism located in the lower portionof the firearm, and a firing pin mechanism which is situated behind thecartridge housing breech. The firing mechanism and the firing pinmechanism are actuated in this order when the trigger is pulled. The twomechanisms comprise several parts which move in sequence upon pressingthe trigger, until the firing pin strikes the rim of the cartridge.Because of the large number of parts included in the said two mechanismsand because these parts are spaced relatively far apart, the time takenfor the firing pin to strike the base of the cartridge after the triggerhas been pulled is relatively long. Attempts have been made to reduce asmuch as possible the time taken to complete this action since the handof the marksman might move during said period, thus impairing theaccuracy of the shot. The firing and firing pin mechanism in firearmsused in competition, such as free pistols, have been developed to suchan extent that it is no longer possible to shorten the period of time inquestion, when using these mechanisms.

The design of prior art firearms can be altered according to the presentinvention in a most surprising manner, so that with the exception of thefiring pin no firing pin mechanism is needed at all. The presentinvention is characterized in that the firing pin is directed from thefront, and moves backwards in such a way that it strikes the leadingedge of the cartridge rim. In this way the firing pin is actuatedimmediately, by the firing mechanism. Since, pursuant to the spirit ofthe invention the number of moving parts are considerably reduced andsince the trigger movement can be transmitted to the firing pin via amuch shorter path than in the case of prior art firearms,

the time interval between the moment of pressing the trigger and themoment of impact of the firing pin is substantially shorter. Duringexperiments it has been determined that this period of time has beenreduced substantially in half. This means in practice that when usingthe firing mechanism according to the invention the cartridge hasalready left the gun barrel when the firing pin of a conventionalfirearm has only just struck the case of the cartridge. Owing to thesmall number of moving parts and their relatively small size, the massis also considerably less than that of the mass of the prior artfirearms. Consequently, the movements effected by the moving parts donot cause the firearm to move, which would otherwise impair the accuracyof the shot.

The invention will now be more fully described with reference to thedrawing which illustrates a free pistol in section.

The drawing illustrates a firing mechanism in cocked position.

The firing mechanism comprises a bolt 11 which is securely threaded intoa scar I, mounted in turn in a boxlike structure E3. The lower end of acatch member 2 mounted in the frame rests under the action of spring 12in a recess in the upper end of the sear 1. Further, the left end of alever 3, as seen from the drawing, mounted in said boxlike structure 13is supported in a recess in the upper end of the catch member 2. Ahammer 4 is supported to bear against and seat in a recess located tothe right of the lever 3, as seen in the drawing; the said hammer 4 alsobeing mounted in the structure 13. The right-hand end of the hammer 4 isactuated by a strong leaf spring 6, which acts to rotate the hammer 4clockwise.

When the trigger or the end of the bolt 11 is squeezed inwards, thecatch member 2 rotates clockwise, releasing the left-hand end of thelever 3. The hammer, loaded by the spring 6, then rotates the lever 3counterclockwise. At the same time the left-hand end of the hammer 4 isreleased from the righthand end of the lever 3, and strikes heavilyagainst the striking pin 5, which strikes against the leading edge ofthe rim of cartridge case it). The annular detonating charge within therim, which is supported at the back by locking piece 15, fires thecartridge.

The firing mechanism is cocked by rotating the lever 7 counterclockwise.The lever 7 is mounted on the same pivot pin as the hammer 4. When thelever 7 is turned counter clockwise, front face of the lever 7 meets thepin 14 projecting from the side of the hammer 4 and the hammer begins torotate counterclockwise thereby opposing force of spring 6. When thehammer 4 meets the right-hand end of the lever 3, the said lever 3 isrotated clockwise. When the left-hand end of the lever 3 snaps into therecess in the catch member 2 the firing mechanism is cocked. Thepressure spring resting against the lower end of the lever 7 returns thelever to its original position.

The reference numeral 8 indicates a setscrew by means of which thepressure of the trigger movement can be regulated. if desired. Thereference numeral 9 indicates a setscrew which supports the spring 6after a firing sequence, and by means of which the action of the spring6 can be adjusted against the rotary movement of the hammer 4, andthereby also the impact of the hammer against the striking pin 5. Thereference numeral 16 indicates an ejector for the case 10 in the lockingpiece 15.

The present invention is not restricted to the embodiments shown anddescribed but may be varied arbitrarily within the scope of the appendedclaims. It is obvious that the members which transmit the movement fromthe trigger I, 11 to the striking pin 5 can be arranged differently fromthe arrangement shown in the drawing.

lclaim:

l. A firearm for firing a projectile from a projectile carryingcartridge, said cartridge including a detonating rim having a frontface, said firearm comprising a housing, means in said housing defininga cartridge chamber for containing said cartridge, said cartridgechamber having a longitudinal axis along which said projectile isejected in a forward direction, a firing pin shiftably supported in saidhousing for engaging said front face of said detonating rim of saidcartridge in a rearward direction substantially opposite of said forwarddirection, impelling means for impelling said firing pin, locking meansfor locking said impelling means in an energy stored condition in spacedrelation relative to said firing pin, and releasing means for releasingsaid impelling means from said locking means such that said impellingmeans impels said firing pin for discharging said cartridge from saidcartridge chamber.

2. A firearm as claimed in claim 1 wherein said impelling means includesa hammer pivotally supported in said housing, and means for urging saidhammer rotatably toward said firing pin.

3. A firearm as claimed in claim 2 wherein said locking means includes alever pivotally supported in said housing, said lever including oppositeend portions, one of said opposite end portions being engageable withsaid hammer for releasably holding said hammer in spaced relationrelative to said firing pin.

4. A firearm as claimed in claim 3 wherein said locking means furtherincludes a catch pivotally supported in said housing, said catchincluding a portion engageable with the other of said opposite endportions of said lever for releasably holding said lever in a positionfor locking said hammer.

5. A firearm as claimed in claim 4 wherein said locking means furtherincludes a spring interposed between said catch and said housing forurging said catch rotatably toward said other of said opposite endportions of said lever.

6. A firearm as claimed in claim 5 wherein said releasing means includesa scar pivotally supported in said housing, said sear including aportion engageable with said catch for rotating said catch away fromsaid lever to free said hammer.

7. A firearm as claimed in claim 6 including means for cocking saidfirearm.

means, said locking means, and said releasing means are constituted by aplurality of pivotally supported nontranslatory members operativelycoupled with one another.

1. A firearm for firing a projectile from a projectile carryingcartridge, said cartridge including a detonating rim having a frontface, said firearm comprising a housing, means in said housing defininga cartridge chamber for containing said cartridge, said cartridgechamber having a longitudinal axis along which said projectile isejected in a forward direction, a firing pin shiftably supported in saidhousing for engaging said front face of said detonating rim of saidcartridge in a rearward direction substantially opposite of said forwarddirection, impelling means for impelling said firing pin, locking meansfor locking said impelling means in an energy stored condition in spacedrelation relative to said firing pin, and releasing means for releasingsaid impelling means from said locking means such that said impellingmeans impels said firing pin for discharging said cartridge from saidcartridge chamber.
 2. A firearm as claimed in claim 1 wherein saidimpelling means includes a hammer pivotally supported in said housing,and means for urging said hammer rotatably toward said firing pin.
 3. Afirearm as claimed in claim 2 wherein said locking means includes alever pivotally supported in said housing, said lever including oppositeend portions, one of said opposite end portions being engageable withsaid hammer for releasably holding said hammer in spaced relationrelative to sAid firing pin.
 4. A firearm as claimed in claim 3 whereinsaid locking means further includes a catch pivotally supported in saidhousing, said catch including a portion engageable with the other ofsaid opposite end portions of said lever for releasably holding saidlever in a position for locking said hammer.
 5. A firearm as claimed inclaim 4 wherein said locking means further includes a spring interposedbetween said catch and said housing for urging said catch rotatablytoward said other of said opposite end portions of said lever.
 6. Afirearm as claimed in claim 5 wherein said releasing means includes asear pivotally supported in said housing, said sear including a portionengageable with said catch for rotating said catch away from said leverto free said hammer.
 7. A firearm as claimed in claim 6 including meansfor cocking said firearm.
 8. A firearm as claimed in claim 7 whereinsaid means for cocking said firearm includes a further lever pivotallysupported in said housing, said further lever including a portionengageable with said hammer.
 9. A firearm as claimed in claim 8 whereinsaid further lever includes a further portion protruding outwardly fromsaid housing for operator manipulation, and said releasing means furtherincludes a member fixedly connected to said sear and protruding fromsaid housing for operator manipulation.
 10. A firearm as claimed inclaim 1 wherein said impelling means, said locking means, and saidreleasing means are constituted by a plurality of pivotally supportednontranslatory members operatively coupled with one another.